Merge pull request #1 from tongming/master

add split script for spliting training file
Merge pull request #2 from tongming/master

fix email address
added a todo.txt
changed todo.txt to todo_yiqian.txt
added subsample.py
updated subsample.py
fixed subsample.py
add a simple python line counter
added: FTRL class,  main function for generating submission.csv
add saving model support